With the development of wireless broadband networks, radio spectrum resources are in urgent need, and cognitive radio (CR) technology is an important means of improving spectrum utilization. Base on the CR technology, a secondary system (unlicensed spectrum user) shares a spectrum with a primary system (licensed spectrum user) in opportunity mode, or with other secondary systems in a public spectrum according to certain spectrum etiquette. The key of spectrum sharing is that the secondary system can rapidly, accurately and reliably acquire status information of an idle spectrum. The acquisition of the status information is based on a spectrum sensing technique in the CR technology.
In actual applications, the spectrum sensing technique involves two key aspects: one is how to enable a CR user to obtain accurate detection information in a noise interference environment, and the other is how to reliably share or report the detection result with low overhead.
In a cellular multi-hop network, a terminal can be connected to a base station of a corresponding cell through one or more relay nodes, so as to reduce the path loss, and greatly increase the capacity and coverage of the entire cell. Therefore, with the increasing applications of cellular multi-hop networks, it is a problem to be addressed by researchers to improve the spectrum utilization in the cellular multi-hop network.